Commands tagged bash String Manipulations (5)

  • This type of join is clearly documented in the bash manual. Only the first character of IFS is used for the delimiter. Show Sample Output


    3
    (IFS=,; echo "${array[*]}")
    aspiers · 2013-09-25 10:36:38 0
  • When you have different digital cameras, different people, friends and you want to merge all those pictures together, then you get files with same names or files with 3 and 4 digit numbers etc. The result is a mess if you copy it together into one directory. But if you can add an offset to the picture number and set the number of leading zeros in the file name's number then you can manage. OFFS != 0 and LZ the same as the files currently have is not supported. Or left as an exercise, hoho ;) I love NF="${NF/#+(0)/}",it looks like a magic bash spell.


    2
    OFFS=30;LZ=6;FF=$(printf %%0%dd $LZ);for F in *.jpg;do NF="${F%.jpg}";NF="${NF/#+(0)/}";NF=$[NF+OFFS];NF="$(printf $FF $NF)".jpg;if [ "$F" != "$NF" ];then mv -iv "$F" "$NF";fi;done
    masterofdisaster · 2010-11-08 22:48:56 2
  • I like to label my grub boot options with the correct kernel version/build. After building and installing a new kernel with "make install" I had to edit my grub.conf by hand. To avoid this, I've decided to write this little command line to: 1. read the version/build part of the filename to which the kernel symlinks point 2. replace the first label lines of grub.conf grub.conf label lines must be in this format: Latest [{name}-{version/build}] Old [{name}-{version/build}] only the {version/build} part is substituted. For instance: title Latest [GNU/Linux-2.6.31-gentoo-r10.201003] would turn to title Latest [GNU/Linux-2.6.32-gentoo-r7.201004]"


    1
    LATEST=`readlink /boot/vmlinuz`; OLD=`readlink /boot/vmlinuz.old`; cat /boot/grub/grub.conf | sed -i -e 's/\(Latest \[[^-]*\).*\]/\1-'"${LATEST#*-}"]'/1' -e 's/\(Old \[[^-]*\).*\]/\1-'"${OLD#*-}"]'/1' /boot/grub/grub.conf
    algol · 2010-04-21 19:16:51 0
  • You define your variable MYVAR with the desired search pattern: MYVAR= ...which can then be searched with the find command. This is useful if you in a script, where you want the arguments to be fed into the find command. The provided search is case insensitive (-iname) and will find all files and directories with the pattern MYVAR (not exact matches). This may go without saying, but if you want exact matches remove the \* and if you want case sensitive, use the -name argument.


    0
    find . -iname \*${MYVAR}\* -print
    Buzzcp · 2010-08-04 05:43:51 0
  • Demos figlet/toilet fonts in a configurable dir. Show Sample Output


    0
    for i in ${TOILET_FONT_PATH:=/usr/share/figlet}/*.{t,f}lf; do j=${i##*/}; toilet -d "${i%/*}" -f "$j" "${j%.*}"; done
    trevorj · 2011-12-27 00:49:42 0

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Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

What is my public IP address
Clean output, if used in scripts: $ GET checkip.dyndns.org|grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' or $ GET icanhazip.com

Unzip multi-part zip archive
Assuming you have a multi-part archive like "archive.zip archive.z01 archive.z02 ...", unzip will not handle these correctly. If you "fix" the parts into one big file with zip -F before, it works.

add all files not under version control to repository
With the force options the same results can be achieved

Search recursively to find a word or phrase in certain file types, such as C code
I have a bash alias for this command line and find it useful for searching C code for error messages. The -H tells grep to print the filename. you can omit the -i to match the case exactly or keep the -i for case-insensitive matching. This find command find all .c and .h files

Follow the flow of a log file
tailf same as tail -f follow the flow of a log file, showing it in real time to stdout.

nmap get all active online ips from specific network
scan whole specific network for active online ips

Random colours at random locations

Backup VPS disk to another host

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials


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